1. Technical Field
The present invention relates to a toner cartridge and an image forming apparatus, and in particular, it relates to a toner cartridge for an image forming apparatus using the electrophotography system of developing an electrostatic image with a toner.
2. Related Art
Conventionally, for the image forming apparatus adopting electrophotographic system such as a copying machine and a laser printer, reduction of the number of replacements by increasing the capacity of the expendable supplies has been required in order to reduce the page cost or the like.
The toner cartridges for supplying a toner to the image forming apparatus includes a toner cartridge of a single-layer bottle type for supplying the toner to the apparatus main body by simply setting the cartridge supply opening to the receiving opening of the main body so as to adjust each other and removing the sealing member that seals the supply opening, and a toner cartridge of a plural-layer cylinder type in which the cylindrical inner case is inserted into the cylindrical outer case and the inner case is rotatable.
In the replacement of the cartridge after the toner supply, since the bottle type cartridge is detached with the toner supply opening in an open state, the residual toner inside the cartridge can easily be scattered so as to pollute the circumference or the like, which give rise to a problem of handling difficulty.
According to the cylinder type cartridge 117 of a cylindrical, plural layer structure as shown in FIG. 11, although pollution by the toner scattering or the like can be prevented by opening and closing of the supply opening by the rotation operation of the cartridge in a state of being mounted on the apparatus main body. However, for enlarging the toner capacity for meeting the demand from the users as mentioned above, since the cylindrical diameter of the cartridge 117 as shown in for example FIGS. 11, 12 should be enlarged, therefore, as the result of enlarging the toner capacity, there is a problem of enlarging also the apparatus main body.